I actually have a question about the robot you described in the page, or more specifically the camera youused. What camera is it, and how is it interfaced by a microcontroller? Or was it hooked up to a computer?

On another note, another tutorial that I'd really like to see would be one on how to design bases for robots.I have some servos, but I'm not really sure how to mount them onto a base, so a tutorial on that would beextremely useful.

The camera is the CMUcam, which is interfaced by a serial cable to the cerebellum microcontroller. I dont actually recommend using the CMUcam, as it caused me way too much frustration to get to work. And it still had unexplainable bugs that I could never fix.

As I was writing this plastics tutorial, it occured to me a tutorial on building robot bases could potentially be useful for people . . . and I also have a lot of 'in-construction' pics of my old robots that I could use too.

I also have a thing against books that have step by step instructions on building a particular robot as it takes out the imagination and fun of building a robot. They also seem to forget to only make a very basic design for a beginner to learn . . .

I guess what I can do is write a tutorial more specifically of attaching parts to a robot base, and the reader can decide which parts to actually use, and where to place these parts, on their own.

I was also thinking of a tutorial on how to build a 4 wheel omni-wheel robot . . . mostly cause I have one as a perfect example. Its really simple and its the only one I have ever seen so far.

Is this in line with what you were thinking? Let me know and I will probably have it written in a week or so.

O and as for attaching servos there are two ways. The first is you can buy what is called 'servo tape' and tape it between two flat plates. Servo tape is very strong and holds well, and it has a little flex to it which acts as a basic suspension system. I only recommend it for light weight robots though. The other way is to mount with screws. A servo has 2 holes on both sides designed for screws to go through, and servos come with 2 black rectangular things with holes in it for mounting with the screws. I used this method for that omni-wheel robot in my tutorial. Let me know if this helps.

I think it would be really useful to have building tips in general, for example tutorials on how to attachmotors securely/easily, the pros and cons of the different methods, kind of like what you did with materialsand actuators. Other stuff that would be nice would be tutorials on designing a base, and how to choosethe right motors and wheels.

While a tutorial on building an omni directional robot would be really cool, and something I would definitely liketo see, I too agree that step by step instructions in books aren't that great.. It's like you might want a robotlike that, but not exactly, but you wouldn't really know how to make changes. What I would suggest would beto maybe have pages describing robots you've built and how you did it (like with the omni directional robot),but also some other tutorials on general strategies that can be applied to a new project.

Regarding cameras, I've been searching online for a long time on how to use a camera on a robot withoutneeding a full fledged PC, and CMUCam is the only one I've found so far. I'm reluctant to use it too, but if I findany other methods to get cameras working on robot microprocessors, I'll definitely post something here.

Well, to get an L shaped bracket, you would need to bend the material 90 degrees. Although this is possible with thin sheets of plastic, aluminum is much stronger and more rigid.

You can however get a block of HDPE and cut it into an L shape. This robot I am working on now actually uses a U shaped peice of HDPE I am buying from mcmaster as my chassis and servo mounting bracket combined. If you search for HDPE on their site you can probably find it and see if its what you want.

I guess the main reason I perfer aluminum though is that this area of your robot will recieve higher forces, and if you arent confident it wont break, aluminum is the safer option.

While writing this last tutorial I got the idea of writing up another tutorial on calculating various forces, torque, velocity, and gearing of robots. Sound useful?

However, it might be a good idea to include all the math and all, but also provide a chart at the bottom or something,that can be used as an easy reference. For example, if the robot is 10 lb, how much torque would be required (orrecommended) by the motors, stuff like that.. So that we can calculate the torque and gearing if we wanted, but there'sstill a rough guideline that can be followed, and also to check that the calculations are right.

Well I have tons of experience with R/C using Hitec handheld controllers and servos. Ive made like 5 different servo operated R/C 'robots' and have also operated a microcontroller with an R/C remote. But I have never made my own R/C device, done wireless through a computer, IR remote operation, or done any other type of remote control with robots. I wouldnt trust my advice on it.

The Hitec controller method is really easy . . . But I am guessing you want the latter method?

Ok it will probably take me 2-3 weeks to write it cause I am writing a few other tutorials too at the moment.

But to get you thinking, and so you know what is involved, here is a quick run down on how to do it.

Get a R/C remote and reciever at any hobby shop.

Connect a servo wire from the reciever to a digital port on your microcontroller.

When your R/C remote sends a signal to the reciever, the reciever outputs a square wave (meant for a servo). The frequency of this square wave changes depending on your R/C remote command.

Your microcontroller can then determine the frequency and initiate your desired commmand.

A mod to this is use a resistor/capacitor circuit to turn the squarewave into an analog voltage, then have your microcontroller analog port just read the voltage to determine the course of action.

I recommend the 2nd option because it involves much less microcontroller processing . . . but I have to figure out what resistor/capacitor values to use and I am too lazy right now to do it =P

I also had a friend hack a servo to do this. Apparently there is some analog pin in the circuitry that when it recieves a reciever squarewave signal, the analog value changes. So theoretically just hook up a servo to your reciever, and solder a wire somewhere on the servo circuit board (use a multimeter and guessing to find the pin) and attach that wire to the analog pin of your microcontroller.

However, it might be a good idea to include all the math and all, but also provide a chart at the bottom or something,that can be used as an easy reference. For example, if the robot is 10 lb, how much torque would be required (orrecommended) by the motors, stuff like that.. So that we can calculate the torque and gearing if we wanted, but there'sstill a rough guideline that can be followed, and also to check that the calculations are right.

i will admit it is a little too much for a beginner, and a little watered down, but to teach you how to design your own circuits would require way more than a one page tutorial. i took several year long university courses to understand this stuff . . .

instead my electronics tutorial explains the very very basics, and i have a schematics/electronics page that should have all your circuits predesigned for you:

i think its just something that you have to learn over time. when i design a circuit, i have to imagine how the electrons flow, and how each component changes that flow. but most of the time i have built something similar already, or i read online how something works.

the schematics i have up explain how they work. you basically need to learn each schematic on your own. after you understand how they work, then you can start to modify them. just copy and reverse engineer them.

it was actually my very first schematic for my very first robot, which i built after spending hours on studying why it works. my first attempt ended up in a meltdown and me burning myself, but my 2nd, and then 3rd, worked really nice.

i will admit that page is a little out dated on my current knowledge, but i think it would really help you learn capacitors and transistors - pratical application.

you can almost build every circuit on your robot without a single calculation, if you understand the basics and imitate other people's circuits.

hello,I would like to know more about line tracersin particular, what sensors would perform best?i have used LED and LDR combination but its response is very slow.I would like to know about cost effective sensors and some algorithms and sensor array types for line tracing